Biomedical subjects

M Pellerin

Publications and source records attributed to M Pellerin.

At least 37 records · Page 2Linked to original sources

PubMed2000

Ten-year follow-up of critically ill patients undergoing heart transplantation.

BACKGROUND: The long-term result following heart transplantation appears very good despite complications of coronary atherosclerosis and cancer. Critically ill patients supported with mechanical devices remain a growing and difficult group in which long-term results need to be defined. The objective of this study was to review the 10-year follow-up of critically ill patients who underwent heart transplantation after support with mechanical devices. METHODS: We retrospectively analyzed all patients who underwent heart transplantation from 1986 to 1999 at the Montreal Heart Institute. RESULTS: Twenty-two patients (22/199, 11%) underwent heart transplantation after support with intra-aortic balloon pumps (n = 17) and total artificial hearts (n = 5). One hundred seventy-seven patients (177/199, 89%) underwent heart transplantation without pre-operative mechanical assistance. Patients with pre-operative mechanical assistance were younger (41 +/- 12 vs 48 +/- 10 years old, p = 0. 002), underwent a shorter waiting time to transplantation (2 +/- 2 vs 19 +/- 27 weeks, p = 0.004), and donor hearts had longer ischemic time (166 +/- 63 vs 137 +/- 49 minutes, p = 0.002) compared with patients without pre-operative mechanical assistance. One-month, 1-, 5-, and 10-year survival averaged 86% +/- 7%, 67% +/- 10%, 67% +/- 10%, and 59% +/- 12%, respectively, in patients with pre-operative mechanical assistance compared with 95% +/- 2%, 88% +/- 2%, 81% +/- 3%, and 74% +/- 4%, respectively, in patients without assistance, a significant difference (p = 0.04) that is mainly related to higher operative mortality in the former group. Although, we found no difference between the 2 groups in the 10-year freedom rate from acute rejection, infection, cancer, and coronary atherosclerosis, sepsis was the cause of 4 early deaths among patients with pre-operative mechanical assistance. CONCLUSION: Early and long-term survival was significantly decreased in critically ill patients with pre-operative mechanical assistance compared with other patients without pre-operative assistance. Sepsis is a dominant threat among patients who underwent heart transplantation with pre-operative mechanical assistance, and the lower survival is due mainly to the increased early mortality.

Adult↗

PubMed2000

Reinfusion of mediastinal blood after heart surgery.

BACKGROUND: Several authors studying autotransfusion of shed mediastinal blood in patients undergoing heart operations have published conflicting results regarding reduction of the need for homologous blood transfusion. The effect on coagulation parameters is also unclear. METHODS: In a prospective randomized study, 198 patients who underwent coronary artery bypass grafting or a valvular operation were divided into 2 groups: a group with autotransfusion of shed mediastinal blood after an operation and a control group. Continuous reinfusion of mediastinal blood was done until no drainage was present or for a period of 12 hours after the operation. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored. RESULTS: The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P =.01). The number of re-explorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was higher in the autotransfused patients compared with control patients (1200 +/- 201 mL vs 758 +/- 152 mL, P =.0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations. CONCLUSION: Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion in patients undergoing various cardiac operations. The cause of increased shed blood in patients undergoing autotransfusion remains unclear.

Analysis of Variance↗

PubMed2000

Clinical outcome after isolated tricuspid valve replacement: 20-year experience.

OBJECTIVE: To examine the early and late results of isolated tricuspid valve replacement (TVR). DESIGN AND SETTING: All isolated TVRs performed at the Montreal Heart Institute, Montreal, Quebec between January 1978 and January 1998 were retrospectively reviewed. Follow-up data on patients were obtained through the valve clinic. PARTICIPANTS: From a total of 79 TVR and 375 tricuspid annuloplasties performed during the study period, 29 patients who underwent 32 isolated TVRs (six mechanical valves and 26 bioprostheses) were included. Patient age ranged from 25 to 70 years (mean 48), and 62% were female. Twenty-seven patients (84%) were in New York Heart Association (NYHA) functional classes III and IV. Previous valve surgery had been performed in 22 patients (69%) among whom nine had undergone TVR. RESULTS: Postoperatively, a permanent pacemaker was implanted in nine patients (28%), and reoperation because of bleeding was required in two patients. Mean follow-up was 67.7 months (93% complete). Serial echocardiography showed prosthesis dysfunction in three patients, requiring two valve re-replacements at 12.8 and 7.7 years after initial surgery. All patients, except three, showed an improvement of their NYHA class. Six patients (19%) died in hospital and seven patients died during late follow-up at a mean of 38.1 months after surgery, including one valve-related death (mechanical valve thrombosis). The actuarial survival rate of all patients was 63% after five years and 47% after 10 years. CONCLUSION: Isolated TVR remains a high risk procedure. Most survivors, however, should expect a better quality of life by the improvement in their NYHA class.

Adult↗

PubMed2000

Effect of mycophenolate mofetil in heart transplantation.

OBJECTIVE: To study the effect of mycophenolate mofetil (MMF), a new immunosuppressive drug that acts by inhibiting de novo pathways of purine synthesis, and rabbit antithymocyte globulin (RATG) on the lymphocyte subpopulation after heart transplantation. DESIGN: A review of clinical and laboratory records. SETTING: The Montreal Heart Institute. PATIENTS: Thirty-one patients who underwent heart transplantation. In 9 patients, neoral cyclosporine, prednisone and azathioprine were administered (group 1). In 14 patients RATG was added during the first 3 postoperative days (group 2) and in 8 patients RATG and combination immunosuppression was given, but MMF was used instead of azathioprine (group 3). The demographic characteristics of donors and recipients were similar among the 3 groups. MAIN OUTCOME MEASURES: The proportion of CD2, CD4 and CD8 receptor-positive lymphocytes, expressed as a mean (and standard deviation) percentage of the total lymphocyte population, measured at 7, 15 and 30 days and 6 months after transplantation. RESULTS: At 7 days after transplantation, CD2 lymphocytes averaged 55% (18%), 16% (15%) and 14% (11%) in groups 1, 2 and 3 respectively (p < 0.05), CD4 averaged 36% (11%), 9% (12%) and 7% (8%) in groups 1, 2 and 3 (p < 0.05), and CD8 averaged 14% (6%), 4% (3%) and 4% (3%) in groups 1, 2 and 3 (p < 0.05). At 15 days after transplantation CD2 averaged 69% (10%), 42% (16%) and 47% (20%) in groups 1, 2 and 3 respectively (p < 0.05), and CD8 averaged 16% (7%), 16% (6%) and 19% (7%) (p = NS). At 30 days after transplantation the percentages of CD2, CD4 and CD8 lymphocytes were similar among the groups. The freedom rate from acute rejection averaged 22% (14%), 9% (8%) and 50% (18%) (p < 0.05) in groups 1, 2 and 3 at 6 months after transplantation, and the freedom rate from infection averaged 56% (17%), 36% (13%) and 38% (17%) for the 3 groups at this time period (p = NS). CONCLUSIONS: A short course of RATG causes severe, transitory depletion of CD2, CD4 and CD8 lymphocyte subpopulations. MMF decreases the incidence of early acute rejection after heart transplantation without affecting the lymphocyte subpopulation when compared with azathioprine.

Animals↗

PubMed2000

Endoscopic saphenectomy for coronary artery bypass surgery: comparison of two techniques with and without carbon dioxide insufflation.

OBJECTIVE: To compare the clinical results of an initial experience with two techniques of endoscopic saphenectomy with and without gas insufflation. DESIGN: A retrospective study was performed between September 1998 and March 1999 on 40 patients who underwent endoscopic saphenectomy for coronary artery bypass graft without (group 1, n=15) and with (group 2, n=25) carbon dioxide insufflation. INTERVENTIONS: In both groups, the site of harvesting was at the knee through a 2 cm incision. In group 1, dissection was performed using a hand-held dissector while in group 2 dissection was performed after ensuring that there was a seal at the knee and insufflation of carbon dioxide. Collaterals were controlled with an endoclipper in group 1 and bipolar scissors in group 2. Intraoperative procedure time, length of the harvested vein and aspect of the thigh (ecchymosis, hematoma, infection) were recorded. RESULTS: Vein trauma occurred in four patients in group 1 (four of 15, 27%) and in one in group 2 (one of 25, 4%). Hematomas developed in four patients in group 1 (four of 15, 27%) and in one patient in group 2 (one of 25, 4%). Wound infection occurred in no patients in group 1 and in one patient in group 2. One patient in group 2 suffered carbon dioxide embolism with no untoward consequences. Conversion to an open technique was necessary in five patients in group 1 (five of 15, 33%) and in two patients in group 2 (two of 25, 8%). CONCLUSIONS: Endoscopic saphenectomy both with and without carbon dioxide insufflation is associated with a low infection rate, but vein trauma and wound hematomas are more common without carbon dioxide insufflation.

Angioscopes↗

PubMed2000

[Isolated tricuspid valve replacement. Long-term results].

The purpose of this study was to examine the early and late results in 29 patients who underwent 32 (6 mechanical and 26 bioprostheses) isolated tricuspid valve replacement (TVR) from a total of 79 TVR and 375 tricuspid annuloplasties performed at the Montréal Heart Institute, between January 1978 and January 1998. Patients' ages ranged from 25 to 70 years (mean 48 years), and 62% were females. Twenty-seven patients (84%) were in New York Heart Association (NYHA) functional class III and IV. Previous valve surgery had been performed in 22 patients (69%) of which 9 had undergone TVR. Postoperatively, permanent pacemaker was implanted in 9 patients (28%), and immediate reoperation was required in 2 patients because of bleeding. Mean follow-up period was 67.7 months (93% complete). Serial echocardiography showed 3 prosthesis dysfunctions, leading to a second replacement in 2 patients at 12.8 and 7.7 years after initial surgery. All but three patients showed an improvement of their NYHA class. Hospital mortality occurred in 6 patients (19%) and 7 patients died during late follow-up: mean 38.1 months after surgery, including one valve-related death (mechanical valve thrombosis). Actuarial survival rate of all patients was 63% after 5 years, and 47% after 10 years. Isolated TVR remains a high-risk procedure. Most survivors, however, should expect a better quality of life with improvement in their NYHA class.

Adult↗

PubMed1999

Comparison of long-term clinical results of double versus single internal mammary artery bypass grafting.

BACKGROUND: The long-term benefits of double versus single internal mammary artery (IMA) coronary bypass grafting have not yet been established. METHODS: Six hundred patients were studied retrospectively 10 years after coronary revascularization using saphenous vein grafts (SVGs) only or single or double IMA grafts. RESULTS: Patients with double IMA grafts were younger and were more likely to have diabetes, left main coronary stenosis, and three-vessel coronary artery disease than patients with SVGs or single IMA grafts. Patients with SVGs and double IMA grafts had a greater number of diseased coronary vessels and a greater number of coronary bypass grafts per patient than patients with single IMA grafts (mean +/- SEM, 2.8 +/- 1.0, 2.8 +/- 0.7, 2.1 +/- 0.8 grafts per patient, respectively, p < 0.0001). Actuarial survival rates 10 years after placement of SVGs and single and double IMA grafts averaged 83% +/- 6%, 90% +/- 4%, and 87% +/- 8%, respectively (p = 0.03). Cox regression analysis showed that diabetes (relative risk, 2.03; 95% confidence interval, 1.55 to 2.66) and chronic pulmonary obstructive disease (relative risk, 2.20; 95% confidence interval, 1.58 to 3.80) increased, whereas an IMA graft on the left anterior descending coronary artery significantly decreased, the risk of death after operation (relative risk, 0.45; 95% confidence interval, 0.36 to 0.57) throughout the follow-up period. CONCLUSIONS: Use of an IMA graft on the left anterior descending coronary artery improves survival compared with use of an SVG. Although patients with double IMA grafts had a greater number of poor prognosis risk factors before operation, their 10-year survival rate was similar to that of patients with a single IMA graft.

Adult↗

PubMed1999

Structural valve deterioration in mitral replacement surgery: comparison of Carpentier-Edwards supra-annular porcine and perimount pericardial bioprostheses.

BACKGROUND: Bioprostheses preserved with glutaraldehyde, both porcine and pericardial, have been available as second-generation prostheses for valve replacement surgery. The performance with regard to structural valve deterioration with the Carpentier-Edwards supra-annular (CE-SAV) porcine bioprosthesis and the Carpentier-Edwards Perimount (CE-P) pericardial bioprosthesis (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) was evaluated to determine whether there was a difference in mitral valve replacement. METHODS: The CE-SAV bioprosthesis was implanted in 1266 overall mitral valve replacements (isolated mitral, 1066; mitral in multiple, 200) and the CE-P bioprosthesis in 429 overall mitral valve replacements (isolated mitral, 328; mitral in multiple, 101). The mean age of the CE-SAV population was 64.2 +/- 12.2 years and that of the CE-P population, 60.7 +/- 11.7 years (P =.0001). For the study, structural valve deterioration was diagnosed at reoperation for explantation. RESULTS: The freedom from structural valve deterioration was evaluated to 10 years, and the freedom rates reported are at 10 years. For the overall mitral valve replacement groups, the actuarial freedom from deterioration was significant (P =.0001): CE-P > CE-SAV for 40 years or younger, 80% versus 60%; 41 to 50 years, 91% versus 61%; 51 to 60 years, 84% versus 69%; 61 to 70 years, 95% versus 75%. The older than 70-year group was 100% versus 92% (no significant difference). The actual freedom from structural valve deterioration also demonstrated the same pattern at 10 years: 40 years or younger, CE-P 82% versus CE-SAV 68%; 41 to 50 years, 92% versus 70%; 51 to 60 years, 90% versus 80%; 61 to 70 years, 97% versus 88%; and older than 70 years, 100% versus 97%. The independent risk factors of structural valve deterioration for the overall mitral valve replacement group were age and age groups and prosthesis type (CE-SAV > CE-P). The prosthesis type either in isolated replacement or in multiple replacement was not predictive of structural valve deterioration. The pathology of structural valve deterioration was different: 70% of CE-P failures were due to calcification and 57% of CE-SAV failures were due to combined calcification and leaflet tear. CONCLUSION: The actuarial and actual freedom from structural valve deterioration, diagnosed at reoperation, is greater at 10 years for CE-P than for CE-SAV bioprostheses. The mode of failure is different, and the cause remains obscure. Long-term evaluation is recommended, because the different modes of failure may alter the clinical performance by 15 and 20 years.

Adolescent↗

PubMed1999

Quantitative angiographic assessment of coronary anastomoses performed without cardiopulmonary bypass.

BACKGROUND: The quality of the anastomosis performed during coronary artery bypass grafting without cardiopulmonary bypass is a current concern, and myocardial wall restraining devices have been designed to optimize results. A quantitative angiographic analysis was performed to assess coronary anastomoses performed on beating hearts. METHODS: We studied 34 patients who underwent coronary artery bypass grafting without cardiopulmonary bypass between February 1996 and April 1997. The left internal thoracic artery was anastomosed to the left anterior descending coronary artery in all patients. Coronary angiograms were performed 4 +/- 2 days after the operation. The diameter of the anastomoses was quantified by computer-assisted analysis of grafts and native coronary arteries at the toe and heel of the anastomosis. RESULTS: Five of the patients who underwent coronary artery bypass without a stabilizer (n = 20) had stenoses of the internal thoracic artery grafted to the left anterior descending coronary artery of more than 50% at the level of the anastomosis proper, 3 had stenoses at the heel of the coronary anastomosis, and 5 had stenoses at the toe. One of the patients in whom a stabilizer was used (n = 14) had a stenosis of more than 50% at the anastomosis, and 1 had stenosis at the heel. Eight patients in whom the anastomoses were performed without stabilization (8/20, 40%) had stenoses of more than 50%, whereas there was only 1 stenosis of more than 50% of coronary luminal diameter among the patients in whom the operation was performed with a stabilizer (P =.02). CONCLUSION: The quantitative angiographic evaluation suggests that left internal thoracic artery graft to left anterior descending coronary artery anastomoses have a lesser degree of intraluminal stenosis when performed with the use of a myocardial wall stabilizer.

Aged↗

PubMed1999

Nitric oxide inhalation in the treatment of primary graft failure following heart transplantation.

BACKGROUND: Primary graft failure from right or left ventricular insufficiency remains a serious cause of early death following heart transplantation. Inhaled nitric oxide (NO) is a potent pulmonary vasodilator that could decrease pulmonary pressure and improve right ventricular function. METHODS: Two cases of early graft failure following orthotopic heart transplantation were treated with NO inhalation. The treatment consisted of inhalation of 20 ppm of NO, introduced 4 to 6 hours following transplantation, in 2 patients supported with high doses of inotropic agents and vasopressors in addition to the intra-aortic balloon pump. RESULTS: In the first and second cases, NO inhalation resulted in a decrease in pulmonary artery pressure, in a decrease in pulmonary vascular resistance and in an increase in cardiac index. In the second patient, systemic oxygenation improved markedly 30 minutes after initiation of NO. In the 2 patients, NO inhalation, mechanical ventilation and the intra-aortic balloon pump were weaned 4 days following transplantation. CONCLUSION: Primary graft failure from donor ischemic damage, reperfusion injury or pulmonary hypertension remains a serious complication. The use of an intra-aortic balloon pump, inotropic agents and of inhaled NO appears to offer the best support for recovery of donor heart function. Primary graft failure from right or left ventricular insufficiency remains a serious cause of early mortality following heart transplantation. Ischemic damage of donor heart, reperfusion injury or pulmonary hypertension are the main causes of early graft failure. Although the cause is multifactorial, treatment of primary organ failure remains difficult with dismal results. The objective of the present study was to review the result of 2 patients with donor right heart failure following heart transplantation treated with inhaled nitric oxide (NO).

Administration, Inhalation↗

PubMed1999

A 10-year experience with intravenous thymoglobuline in induction of immunosuppression following heart transplantation.

BACKGROUND: Intravenous thymoglobuline (125 mg a day for 3 days, Institut Mérieux, France) has been used to induce immunosuppression following heart transplantation. Cyclosporine and prednisone, with and without azathioprine or mycophenolate mofetil were used as maintenance immunosuppression. OBJECTIVE: The objective of the study was to determine the clinical effect of antibody induction of immunosuppression following heart transplantation. METHODS: A retrospective analysis of the clinical experience at the Montreal Heart Institute. From 1988 to 1998, 163 patients were administered a 3-day course of intravenous thymoglobuline immediately following heart transplantation (Group 1). From 1983 to 1987 and during an isolated period in 1994, intravenous and oral cyclosporine was used immediately following heart transplantation in 48 patients (Group 2). Routine endomyocardial biopsies were performed in all patients and only moderate and severe rejection was treated. RESULTS: One, 5- and 10-year actuarial survival rate averaged 85%+/-3, 77%+/-4 and 67%+/-5 in Group 1 compared with 88%+/-5, 81%+/-6 and 76%+/-6 in Group 2 (p = 0.5). At 1 year, the freedom rate from an episode of acute rejection averaged 43%+/-4 in Group 1 and 30%+/-7 in Group 2 (p = 0.03) and the freedom rate from an episode of infection averaged 44%+/-4 in Group 1 and 31%+/-7 in Group 2 (p = 0.2). At 1, 5 and 10 years, the freedom rate from graft coronary artery disease averaged 93%+/-2, 68%+/-5 and 50%+/-7 in Group 1 compared with 93%+/-4, 58%+/-8 and 30%+/-8 in Group 2 (p = 0.1) and the freedom rate from cancer averaged 98%+/-1, 91%+/-3 and 67%+/-8 in Group 1 compared with 100%, 95%+/-3 and 77%+/-8 in Group 2 (p = 0.2). There was no side-effect related to the systemic injection of thymoglobuline. CONCLUSION: In a cyclosporine based protocol of immunosuppression, induction with an initial 3-day course of intravenous thymoglobuline is associated with a lower rate of acute rejection. Moreover, the risk of infection and of developing cancer is not increased whereas there was a trend towards a lower incidence of coronary atherosclerosis 5 and 10 years after transplantation.

Adult↗

PubMed1999

Evolution of the hepatitis C virus second envelope protein hypervariable region in chronically infected patients receiving alpha interferon therapy.

Sustained hepatitis C virus (HCV) RNA clearance is achieved in 8 to 12% of patients with chronic HCV infection treated with alpha interferon (IFN-alpha) at the approved dose of 3 MU three times a week for 6 months and in about 25% of those receiving this treatment for 12 months. We used single-strand conformation polymorphism analysis combined with cloning and sequencing strategies to characterize the genetic evolution of HCV second envelope gene hypervariable region 1 (HVR1) quasispecies during and after IFN therapy in patients who failed to clear HCV RNA. Sustained HCV RNA clearance was achieved in 6% of patients. Profound changes in HVR1 quasispecies major variants were estimated to occur in 70% of the patients during and after therapy. These changes were evolutionary and were characterized by shifts in the virus population, related to selection and subsequent diversification of minor pretreatment variants. The quasispecies changes appeared to be induced by changes in the host environment likely resulting from the IFN-induced enhancement and post-IFN attenuation of neutralizing and possibly cytotoxic responses against HVR1. The remaining patients had no apparent changes in HVR1 quasispecies major variants, suggesting selection of major pretreatment variants, but some changes were observed in other genomic regions. We conclude that IFN-alpha administration and withdrawal profoundly alters the nature of circulating HCV quasispecies, owing to profound changes in virus-host interactions, in patients in whom sustained HCV RNA clearance fails to occur. These changes are associated with profound alterations of the natural outcome of HCV-related liver disease, raising the hypothesis of a causal relationship.

Adolescent↗

PubMed1999

[An MRI study of the normal pelvis in the immediate postpartum period].

PURPOSE: To describe the MR findings of the pelvis in the early post-partum period, after vaginal delivery or cesarean section. MATERIALS AND METHODS: Fifteen asymptomatic patients were imaged using a 1.5 Tesla MR unit between 1 and 7 days following delivery. Eight patients had a vaginal delivery, and seven patients had a cesarean section. RESULTS: The following items were evaluated: uterus size, architecture, and contents; uterine and abdominal wall scars; parametrium; peritoneal cavity; ovarian veins. CONCLUSION: MRI provided a good evaluation of the pelvic changes related to pregnancy and delivery. Knowledge of the normal findings should improve diagnosis of early post-partum complications.

Abdominal Muscles↗

PubMed1999

Beating heart coronary artery bypass grafting: technical aspects and results in 200 patients.

OBJECTIVE: To describe the initial experience of the first 200 patients who underwent coronary artery bypass grafting (CABG) on beating hearts at the Montreal Heart Institute, Montreal. DESIGN: A prospective cohort of 200 patients was analyzed to study immediate and short term (two-year follow-up) results. SETTING: Patients underwent CABG at the Montreal Heart Institute from February 1996 to June 1998. The first 30 patients underwent CABG without the use of a myocardial wall stabilizer (group 1), and a myocardial wall stabilizer was used in the following 170 patients (group 2). PATIENTS: Group 1 patients averaged 60+/-10 years of age compared with 66+/-10 years in group 2 (P=0.002). Twelve patients (40%) in group 1 had unstable angina compared with 107 patients (63%) in group 2 (P=0.03). INTERVENTIONS: Group 1 patients underwent 1.7+/-0.7 CABG per patient compared with 2.4+/-0.8 grafts per patient in group 2 (P=0.001). Sixty-seven patients (39%) in group 2 had an obtuse marginal coronary artery grafted, and 145 patients (73%) of both groups had a complete myocardial revascularization. RESULTS: Ten patients (5%) in both groups were converted to cardiopulmonary bypass during surgery. Seven patients (3.5%) died postoperatively: five from myocardial infarction, one from aortic dissection and rupture, and one from arrhythmia. Seventeen patients (8.5%) suffered a perioperative myocardial infarction. In groups 1 and 2, respectively, actuarial survival was 100% and 95+/-2%, and freedom rate from reoperation, percutaneous balloon dilation and recurrent myocardial infarction averaged 93+/-4% and 97+/-2% 18 months following CABG. CONCLUSION: CABG on beating hearts appears to be an alternative approach to the use of cardiopulmonary bypass in selected patients.

Aged↗

PubMed1999

Videoassisted thrombectomy of mechanical prosthetic heart valves.

BACKGROUND AND AIM OF THE STUDY: Thrombosis of a bileaflet mechanical heart valve is a life-threatening clinical event. Surgical thrombectomy of bileaflet mechanical prostheses remains an appropriate treatment in selected patients. METHODS: Between 1996 and 1998, five patients (three men, two women; average age 56 +/- 1 years; range: 56 to 66 years) with thrombosis of left-sided bileaflet mechanical valves were treated with videoassisted thrombectomy of the prosthesis. Four patients had thrombosis of a bileaflet mitral mechanical valve, and one patient had thrombosis of an aortic valve prosthesis. Preoperatively, patients were in either NYHA functional class IV (n = 4) or class I (n = 1). Surgery was performed through a right anterior thoracotomy or a median sternotomy. A rigid 30 degrees thoracoscope was inserted into the left atrium or aorta to visualize the thrombosed valve. The thrombus was extracted and the prosthesis under-surface examined and cleaned. Leaflet mobility, assessed with transesophageal echocardiography, was normal following surgical thrombectomy. RESULTS: Mean cardiopulmonary bypass time was 102 +/- 30 min; mean aortic cross-clamping time was 47 +/- 25 min. There was no hospital mortality; mean hospital stay was 9 +/- 1 days (range: 6 to 11 days). Anticoagulation with intravenous heparin was resumed 24 h after surgery. Three patients were discharged on coumarin treatment alone; two patients received aspirin plus coumarin. Mean postoperative follow up was 7 +/- 8 months (range: 1 to 21 months). One patient died 21 months after thrombectomy of a mitral prosthesis, with an unconfirmed diagnosis of recurrent mitral valve dysfunction. At 1-15 months after surgery, four patients are in NYHA class I, without evidence of prosthesis dysfunction. CONCLUSION: Videoassisted thrombectomy of a bileaflet mechanical heart valve is a treatment option in patients with acute thrombosis of the prosthesis.

Anticoagulants↗

PubMed1999

Conversion of cyclosporine A to tacrolimus following heart transplantation.

BACKGROUND: Cyclosporine A (CyA) is ususally the immunosuppressive drug of choice in organ transplantation; however, some side effects have limited its use. Tacrolimus is a novel immunosuppressive drug that is more potent than CyA, and has been used as a rescue agent following heart transplantation when the use of CyA is undesirable or inefficient. PATIENTS AND METHODS: Since 1996, 14 heart transplant recipients under CyA were switched to tacrolimus therapy, for refractory rejection or intolerance, to conventional immunosuppression. RESULTS: After a mean of 35+/-7 months of treatment, tacrolimus was substituted for CyA therapy. The reason for substitution was refractory rejection in six patients, gingival hypertrophy in five patients, hypertrichosis in one patient, severe arterial hypertension in one patient and hepatotoxicity in one patient. Five patients underwent a successful rescue therapy and one patient died of refractory rejection despite the use of tacrolimus. All patients with CyA side effects recovered with tacrolimus. After conversion from CyA to tacrolimus, the number of episodes of acute rejection decreased from a mean of 0.42+/-0.17 to 0.14+/-0.09 episodes/patient/month under CyA and tacrolimus therapy (P=0.11), respectively. The mean dose of prednisone was 0.18+/-0.06 mg/kg/day before compared with 0.06+/-0.01 mg/kg/day after conversion from CyA to tacrolimus (P=0.09). Creatinine serum levels averaged 124+/-7 mmol/L under CyA treatment compared with 113+/-7 mmol/L with tacrolimus therapy (P=0.002). CONCLUSION: In patients with refractory rejections or intolerance to CyA after heart transplantation, conversion to tacrolimus-based immunosuppression is safe and effective.

Adult↗

PubMed1999

[Results of surgery after failed mitral percutaneous dilatation].

OBJECTIVES: Percutaneous balloon mitral valve commissurotomy (BMC) is an alternative to surgical commissurotomy. Complications following BMC includes mitral regurgitation, iatrogenic atrial septal defect, residual mitral stenosis, and pericardial hemorrhage. This study analyzes the outcomes of surgery following failed BMC for mitral stenosis. METHODS: In a series of 298 patients treated with BMC, 53 patients (17.7%) had a complication that necessitated a surgical treatment. Twenty-eight patients needed an immediate surgery before the discharge (group I) and 25 patients were operated on an elective basis (group II). RESULTS: In group I, 27 patients have been operated and one died before the operation. In 21 patients an acute mitral regurgitation occurred, 3 patients had a residual mitral stenosis, and 3 had a left atrial perforation. The operation consisted of 26 mitral valve replacements, 20 concomitant reparations of iatrogenic atrial septal defect, and one open mitral valve commissurotomy. Operative mortality was 3.7% (1 out of 27). In group II, 25 patients have been operated at a mean 18 +/- 14 months after BMC. In the 25 patients the operation was indicated for significant mitral regurgitation (2 + and more). The operation consisted of 25 mitral valve replacements, 9 concomitant reparations of iatrogenic atrial septal defect, 3 patients had also coronary artery bypasses. The operative mortality was 8% (2 out of 25). The echocardiographic score was similar for both groups, it was 8.4 +/- 2.0 in group I and 8.0 +/- 1.5 in group II (P = NS). Despite these complications following failed BMC, surgery appears a safe procedure with an acceptable mortality.

Aged↗

PubMed1998

GB virus C (GBV-C) infection in patients with chronic hepatitis C. Influence on liver disease and on hepatitis virus behaviour: effect of interferon alfa therapy.

The aim of this study was to evaluate, in patients with chronic hepatitis C, 1) the prevalence and the epidemiological characteristics of GB virus C (GBV-C) infection, 2) the influence of GBV-C on hepatitis C virus (HCV) infection, 3) the pathogenicity of GBV-C in the absence of treatment and under interferon therapy, and 4) the effect of interferon alfa on GBV-C and HCV replications. One hundred fifteen patients with chronic hepatitis C were studied. Before treatment, they were tested for GBV-C RNA by PCR and GBV-C genotype was determined for positive samples. Pretreatment information was collected, including age, gender, source of HCV, estimated duration of HCV infection, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score on liver biopsy, HCV genotype, HCV viral burden and anti-HCV core IgM antibodies. The genetic complexity of the hypervariable region 1 (HVR1) of HCV was studied by PCR-Single Strand Conformation Polymorphism. All patients were treated with 3 to 9 mega units of interferon alfa-2a three times per week for 3 to 6 months. The influence of GBV-C on the evolution of ALT and HCV replication during and after treatment was studied, and GBV-C and HCV RNA were monitored monthly by PCR during this period. Eighteen patients (16%) were GBV-C RNA-positive. Among 11 samples studied, GBV-C genotype 2a was present in 9 cases, 2b in one case and type 3 in one case. GBV-C RNA-positive patients were significantly younger than GBV-C RNA-negative ones (38.4 +/- 11.5 vs. 47.4 +/- 14.0, P = 0.012), a result independent of the route of transmission and the disease duration. No difference between GBV-C RNA-positive and -negative patients was found for other epidemiological parameters (e.g. gender, risk factor for parenteral viral infections, disease duration and HCV genotypes), or for the characteristics of HCV infection and related liver disease (e.g. HCV RNA level, genetic complexity of the HVR1, anti-HCV core IgM, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score). GBV-C did not influence the rates of ALT normalization at months 3, 6 and 12 and of sustained hepatitis C virological response at month 12 of treatment follow-up. During treatment, GBV-C viremia became undetectable in 12 patients (67%) but relapse occurred after treatment withdrawal in all the nine patients with sufficient follow-up. In the remaining six patients (33%), GBV-C resisted interferon. Whatever the effect of interferon on GBV-C replication, the ALT levels correlated with the presence of HCV RNA. In conclusion, GBV-C infection is frequent in patients with chronic hepatitis C, who are mainly, but not exclusively, infected by GBV-C genotype 2a. GBV-C positive patients are significantly younger than GBV-C negative ones. GBV-C does not seem to affect HCV replication, liver disease and responses of HCV infection and liver disease to interferon therapy. GBV-C is sensitive to 3 mega units of interferon alfa administered three times per week in two-thirds of the patients, but relapse is constant with this dosage after treatment withdrawal.

Adult↗